Oil cooler



Allg 14, 1934- A. TEBALDI 1,969,864

v OIL COOLER Filed 0G11. 10, 1932 2 Sheets-Sheet l A. TEBALDI I Aug; 14, 1934 on. coQLER Filed oct. 1o, 19:52 2 sheets-sneer 2 Patented Aug. 14, 1934 OIL COOLER Alessandro Tebald, Milan, Italy Application October 10, 1932, Serial No. 637,184 In Germany October 2.2, 1931 17 Claims.

In connection with radiators for cooling oil and particularly lubricating'oil for aircraft engines and generally for machines and engines, it is known to use by-pass valves loaded by a suitable spring and interconnecting the radiator inlet and outlet ducts, such by-pass valves being intended to provide for a direct ow of oil to the engine or the like when oil is cold and there is therefore too much resistance against its ow through the radiator.

Such provision is defective in that when the radiator is very cold and oil within it is very viscous, the whole amount of oil conveyed by the oil circulating pump discharges through said by-pass valve and such flow through the bypass valve tends to continue even when the oil has reached a very high temperature, because the hot oil does not pass through the radiator which remains cold owing to the action of the cooling iiuid thereon, the flow of liquid through it being thus permanently restricted.

The present invention has for its object a radiator in which the drawback above referred to is removed in that a by-pass valve is provided in the radiator at the outlet thereof, so that the oil must ow through at least a portion of the radiator. Therefore the hot oil owing through the radiator he ts; the same radiator and the oil enclosed therei and makes such oil uid thus assisting -progressively the normal cir culation of oil through the radiator.

The present invention comprises further an arrangement providing for an oil circulation through the radiator which progressively increases with the decrease of resistance against such circulation. L

An embodiment of this invention is shown by way of 'example on the annexed drawings and Figure l is alongitudinal section of a radiator on line 1-1 of Fig. 5, with portions removed;

Figure 2 is a view of the internal member of the radiator, said View being developed in a plane and extending through arc 2-2 of Figure 5;

Figure 3 is a section on line 3-3 of Figure 6;

Figure 4 is a fragmentary section on line 4-4 of Figj;

Figure 5 is in its top half a section on line 5-5 of Fig. 3 and in itsbottom half a section on line 5-5 of Fig. 1;

Figure 6 is a section en line 6-6 of Figures 1 and 3.

As shown on the drawings, the radiator ff this invention comprises an internal tubular member 1 having a ange 3 at one end and having heat radiating fins 2 in its internal surface, a number of such ns being omitted in Fig. 1. A sleeve 4 havingouter heat radiating ns 5 is inserted over member 1 and is held inposition by means of a screw-threaded collar 6 which is screwed on the end of member 1 opposed to its end ange 3 said collar acting to force sleeve 4 against a ring 7 encircling the member 1 and abutting its ang'e 3. The joints intermediate the described parts are sealed by packing members 8, 9, 10, and 11.

The path for oil circulation through the radiator is provided by grooves 12, 12', 12" cut in the outer surface of member 1 and leaving intermediate longitudinal ribs 13, 13' which connect alternately with annular end ribs 14, 14' and leave 'end passages 15, 15' interconnectng the adjacent grooves 12, 12 and 12 as shown in Fig. 2.

At one of their ends member 1 and sleeve 4 provide a circumferential groove 16 into which opens the inlet port 17 (Figures 3 and 5); ducts 18, 18 having a larger sectional area than grooves 12, 12 originate from said groove 16 and communicate at their opposed ends with passages 15f between adjacent grooves 12, said ducts 18, 18 being closed at last named ends'by'annular rib 14'. Flange 3, ring 7 and portions of the wall of the outer sleeve 4 form an :annular collecting duct 19 lying at the radiator end opposed to that where the inlet port 17 is provided, said duct 19 leading to an outlet port 20 provided in ring 7. Duct 19 is divided from grooves 12, 12' and ducts 18, 18 by a partition 4' extending from sleeve 4, and a ring 21 located as an extension of partition 4 between partition 4' and the annular rib 14'.

The illustrated embodiment comprises two main ducts 18, 18, but of course they may be provided in any desired number on the outer surface of member 1, their total cross sectional area being in any case adapted to permit the flow of the maximum amount of oil which is required to pass through the radiator.

At equal distances from each pair of ducts 18, 18 the nal grooves 12" of the path for liquid open directly into the main or collecting duct 19, asshown in Fig. 2. w A

In each of passages 15', which lie at one end of passages 18, 12 and 12 is a port opening through the ring 21 into theduct 19. Each port 22, 22',` 22" is provided with a shutter 23, 23

the action of a resilient loading member as hereinafter described. 1

In the illustrated embodiment said resilient loading means directed to close shutters 23, 23', 23" include a wire25 which bears on said shut'- ters, the ends of said wire passing under pulleys 27 and being engaged by means of an adjusting screw plug 29 in a perforated plunger 28 loose within outlet passage 20. Said plunger 28 is under the action of a spring 30 which abuts on the flange 31 of passage 2O and acts to draw the ends of wire 25 outwardly and to force said wire radially on shutters 23, 23', 23 thus forcing them against their respective ports 22, 22', 22]. f

Ports 22, 22', 22" have different sizes and shutters 23, 23', and 23" on which the wire 25 bears, extend different distances radially from the axis XX,l there being antifriction members 33 between the shutters and wire; thus the tension 'of wire 25 produces different radial actions on said shutters such actions being larger in respect of shutters which are of greater thickness and whose point of contact with wire 25 is therefore more spaced from radiator longitudinal axis X--X while they are reduced in respect of shutters having less thickness.

Ports 22, 22' and 22" between the duct 18 and the -discharge groove 12" are of progressively increasing size, port 22 at the end of duct 18 being the smallest, and port 22" adjacent groove 12" being the largest. The shutter 23 for the small port 22 is thicker, that is, it projects a greater distance from the axis X-X than the shutter 23' for port 22 and the shutter 23" for port 22" projects less than shutter 23". Therefore, the wire 25 presses the shutter 23" less irmly against its port 22" than the shutters 23 and 23 are pressed against the ports 22 and 22. The largest port, 22" will therefore be opened by a smaller oil pressure than ports 22 and 22. As the pressure increases, ports 22 and 22 will be opened.

In operation, when the radiator has reached its normal temperature of operation, the oil conveyed thereinto by a pump (not shown) throughinlet passage 17, enters annular groove 16 and thereafter it flows to main duct 19 through ducts 18 and grooves 12, 12' and 12" of each set, the back pressure of oil under these conditions e,being low due to.fluidity of oil when hot; therefore under these conditions shutters 23, 23', 23 are closed under loading action of wire 25 and spring 30, and the oil flows through the respective passages 18, 12, 12', and 12 and discharges into main 19.

When the temperature of radiator and oil decreases the oil viscosity increases and then the4 back pressure Within radiator increases, this fact causing shutters 23"23', 23 to-open after each other, starting from those having a larger area and subject to a lower pressure by wire 25 and spring 30; therefore shutters 23" are caused to open and oil flows to main 19 through ports 22 without flowing through subsequent grooves 12, and 12". When the temperature decreases further and back pressure increases, shutters 23" and iinally shutters 23 are caused to open; then oil flows from inlet port 17 directly to main 19 and to outlet 20 through ducts 18, 18.

Thus the radiator body is permanently heated by hot oil flowing always through aA portion (ducts 18) of, it even when the 'radiator is substantially inoperative.

On theA contrary, when the temperature is rising in the radiator, the viscosity and back pressure of oil are dropping and then shutters 23, 23' and 23" close in succession, the oil being caused to ow through the full cooling path provided by grooves 12, 12', 12".

In any case hot oil is Vat any time caused to ow through at least a portion of the radiator and thus such radiator never is entirely cut off from the path of hot oil said oil ilowing always through ducts 18, 18; therefore said oil progressively heats adjacent grooves 12 and tends to maintain the radiator in condition for its normal operation. 4

What I claim as my invention and desire .to secure by United States Letters Patent is:-

1. A radiator for cooling viscous liquids comprising a radiator body having an inlet and anv outlet, a passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage end of said duct, means providing a path for iluid to be cooled in radiator body and leading from the outlet passage end of said duct to said outlet passage, said path comprising a number o! sections each having a port opening into said outlet passage,

by-pass valves each controlling one of said path .ports and means tending to hold said by-pass `valves closed, said by-pass valves being adjusted to open in progression beginning from the most remote one from said duct on an increase of zack-pressure occurring within said radiator ody.

2. A radiator for cooling viscousliquids comprising a radiator body having an inlet and an outlet, a passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve' at the outlet passage end of said duct, means providing a path for uid to be cooled in said radiator body and leading from the outlet passage end of said duct to said outlet passage, said path comprising a number of sections each having a port opening into said outlet passage, by-pass valves each controlling one of said path D0rts and means tending to hold -saidv by-pass valves closed, said by-pass valves having different areas subject to back-pressure within said radiator to open and close in progression under varying back-pressures within said radiator body.

v3. A radiator for cooling viscous liquids comprising a radiator body having an inlet and an outlet, a passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, 'a bypass valve at the outlet passage end of said duct, means providing a path for fluid to be cooled in said radiator body and leading from the outlet passage end of said duct to said outlet passage, said path comprising a number of sections each having a port opening into said outlet passage, by-,pass valves each controlling one of said path p orts and means tending to hold said by-pass valves clod, said by-pass valves having increasing areas subject to back-pressure within said radiator beginning from the outlet passage end of said duct to vopen in succession beginning from the most remote one from the outlet passage end of said duct on an increase of back-pressure within said radiator in said radiator beginning from the outlet pas- 4. A radiator for cooling viscous liquids comprising a radiator body having an inlet and an outlet, a passage communicating with said Aoutlet, means in said body providing a duct leading from said inlet to said outlet passage, a

by-pass valve at the outlet passage end of said duct, means providing a path for iluid to be cooled in said radiator body and leading from the outlet passage end of said duct to said outlet passage, said path comprising a number of sections each having a port opening into said outlet passage, by-pass valves each controlling one of said section ports, and means loading said by-pass valves, said by-pass valve loading means exerting different actions on said bypass valves to cause them to open and close in progression under varying back-pressures Within said radiator body.

5. A radiator for cooling viscous liquids comprising a radiator body having an inlet and an outlet, a passage communicating with said outlet, means in saidbody providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage end of said duct, means providing a path for fluid to be cooled in said radiator body and leading from the outlet passage end of said duct to said outlet passagesaid path comprising a number of sections each having a port opening into said outletpassage, by-pass valves each controlling one of said section ports, and means loading saidv by-pa'ss valves, said by-pass valve loading means exerting decreasing actions on said several by-pass valves beginning from the outlet passage end of said duct to cause said by-pass valves to open and close in progression with respect to the most remote one from the outlet passage end of said duct on an increase of backpressure within said radiator body.

6. A radiator for cooling viscous liquids comprising a radiator body having an inlet and an outlet, a passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage end of said duct, means providing a path for fluid to be cooled in said radiator body and leading from the outlet passage end of said duct to said outlet passage, said path comprising a number of sections each having a port opening into said outlet passage, by-pass valves each controlling one of said-section ports, means tending to holdsaid by-pass valves closed, said by-pass valves having different areas subject to backpressure within said radiator, and means loading all said by-pass valves said by-pass valve loading means exerting different actions on said bypass valves to cause them to open and close in progression under varying back-pressures Within said radiator body.

7. A radiator for cooling viscous liquids comprising a radiator body having an inlet and an outlet, a passage communicating with said outlet, means in said body providing a duct leading -se'ction ports, means tending to hold all said by-pass valves closed, said by-pass valves having increasing areas subject to back-pressure withsage end of said duct, and means loading said by-pass valves, said by-pass valve loading means exerting decreasing actions on said several bypass valves beginning from the outlet passage end of said duct to cause said by-pass valves to open and close in progression with respect to the most remote one from the outlet passage end of said duct on an increase of back-pressure within said radiator body. V

8l A radiator for cooling viscous liquids comprising a radiator body providing an inlet and an outlet, a passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage erid of 'said duct, means in said radiator body providfwithin said radiator.

9. A radiator for cooling viscous liquids comprising a cylindrical hollow radiator body providing an inlet and an outlet, an annular passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage end of said duct, means in said radiator body providing anumber of adjacent grooves connected with each other at their alternate opposed ends, the first one of said grooves being connected with the outlet passage end of said duct and the last one opening into said outlet passage, the intermediate ones of said grooves having ports leading to said outlet passage at a number of their interconnection points, by-pass valves each controlling one of said ports and loading means for said by-pass valves, said by-pass` valves being adjusted to open in progression beginning from ythe most remote one from said duct on an increase of back-pressure occurring within said radiator.

10.v A radiator for cooling viscous liquids comprising a cylindrical hollow radiator body providing an inlet and an outlet, an annular passage communicating with said outlet, heatradiating ns on the surfaces of sa-d body, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage end of said duct, means in said radiator body providing a'number of 'ad-1 jacent grooves connected with each other at vtheir alternate opposed ends, the. rst one of said grooves being connected wLth the outlet passage end of said duct and the last one opening into said outlet passage, the intermediate ones of said grooves having ports leading to said outlet passage at a number of their interconnection points, Aby-pass valves each controlling o ne of said ports and loading means for said by-pass valves, said by-pass valves being adjusted to open in progression beginningvfromthe most remote one from said duct on an in crease o! back-pressure occurring within said radator.- i

11. A radiator for cooling viscous liquids comprising a radiator body consisting of two conI centric sleeves having annular grooves at their nular outlet groove end of'said duct and the lasty one opening intosaid annular outlet groove, the intermediate ones of said adjacent longitudinal grooves having ports leading to said annular outlet groove at a number of their interconnection points, lay-pass valves each controlling one of said ports and loading means for said bypass valves, said by-pass valves being adjusted to open in progression beginningy from the most remote one from saidv duct on an increase' of back-pressureoccurring within said radiator.

12. A'radiator for coolingr viscous liquids comprising a cylindrical f radiator body providingr an inlet and an outlet, an annular passage communicating with said outlet, means insaid body providing a duct leading from said inlet to said outlet passage, aby-pass valve at the outlet passage end of said duct, means in said radiator body providing anumberv of adjacent grooves connected with each other at their alternate opposed ends, the first one of said kgrooves `being connected with the outlet passage yendy ofy said duct and the last one opening into said outlet passage,y the intermediate ones of `said grooves having ports leading vto ysaid.' outlety passage at a number of their interconnection points, by-pass valves each controlling one of said ports, a wire embracing said by-pass valves and spring means tensioning said wire t0 load. said by-pass valves, said by-pass valves being adjusted to open in progression beginning from the most remote one from said duct on an increase of back-pressure occurring within said radiator.

13. A radiator for cooling viscous liquids comprising a cylindrical radiator body providing an inlet andan outlet, an annular passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage end of said duct, means in said radiator body'providing a number of adjacent` grooves connected with each other at their alternate a wire embracing said by-pass valves and adv justable spring means tensioning said wire to load said by-pass valves, said by-pass valves being adjusted to open in progression beginning from the most remote one from said duct on an` increase of back-pressure occurring within said radiator.

14. A radiator for cooling viscous liquids comprising a cylindrical radiator body providing an inlet and an outlet, an annular passage communicating with said outlet, means in said body having ports 'leading to said outlet passage at a number of their interconnection points, by pass valves each controlling one oi said ports, said valves having different heights, a wire embracingsaid valves and spring means tensioning said wire, said by-pass valves being arranged to 'open-in progression beginning from the moet remote one from said duct on an increase ofr back-pressure occurringy within said radiator.

15. A radiator for cooling vviscous liquids comprisingk a cylindrical radiator body providing an inlet and an outlet, an annular passage communicating with said outlet,'meansin said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at theyoutlet passage vend of vsaid duct, meansy insaid radiator body providing a number of adjacent grooves connected with each other at their alternate opposed ends, vthe iirst one of saidr grooves being connected with the outlet passage 'end of said yductand the last one opening into said outlet passage,.,the intermediate onesy of said grooves having ports leading to said outlet'passage at a number, of ytheir interconnection points, by-pass valves each controlling yoner offsaid ports, said valves having decreasing heights beginning from ythat of the by-pass valve of the outlet passage end of said duct,-a wire embracing :said valves and spring means tensioning said'wire, to cause said by-pass valves to open in progression beginning from the most remote one from said duct on an increase of back-pressure occurring within said radiator. v

16. A radiator for cooling viscous liquids comprising a cylindrical radiator body providing an inlet and an outlet, anannular passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a by-pass valve at the outlet passage end of said duct, means in Vsaid radiator body providing a number of adjacent grooves connected with each other at their a1- ternate opposed ends, the ilrst one of said grooves being connected with the outlet passage end of said duct and the last one opening into said outlet passage, the intermediate ones of said grooves having voorts leading to said outlet passage at a number of their interconnection points, by-pass valves each controlling one of said ports said by-pass valveshaving increasing area subject to back-pressure within said radiator beginning from that of said duct, said valves having decreasingl heights beginning from that of the said by-pass valve of said duct, a wire embracing said valves and spring means tensioning said wire, to cause said bypass valves to open in progression beginning from the most remote one from said duct on an increase of back-pressure occurring within said radiator.

1'?. A radiator for cooling viscous liquids comprising a radiator body having an' inlet and an j outlet, a passage communicating with said outlet, means in said body providing a duct leading from said inlet to said outlet passage, a bypass valve at the outlet passage end of said duct,

said valve being adjusted to open under a pre- I each controlling one of said ports and means tending to hold said by-pass valves closed, said valves being adjusted to open under pressures of the liquid less than-the opening pressure of `said first named by-pass valve located in said duct.

' ALESSANDRO TEBALDI. 

